The present invention relates to a technology which manages access to a device coupled to a server over a network. The invention particularly relates to a technology that allows safe and easy, remote operations in a system in which the device is virtually available as in the case where it is directly coupled to the server.
Available data transfer bandwidth per person in communicating over a network such as the Internet or an intranet has been broadened than ever. In addition to access from corporate in-house instruments to outside servers, one can even access corporate in-house instruments from home, hotel, hotspot, or other places at a bandwidth of several Mbps to several tens of Mbps. Full-time and inexpensive connection to the Internet from home or in urban areas is now available.
Information instruments such as personal computers (PCs), Personal Digital Assistants (PDAs), and cellular phones have been falling in price, allowing more enterprises to provide most of their employees with terminal devices for their business activities. Many enterprises have allowed their employees to access corporate in-house instruments such as servers and PCs by using information instruments outside their offices, for example, on business trips, at homes, or during traveling for performing their business activities in a prompt manner.
Such access is referred to as remote access functionality, in which a server with virtual private network (VPN) functionality for encrypted communication is installed in-house and the server controls the communication with external information terminals, for example, by encrypting the communication along the communication path. As the external remote access becomes common practice, work systems are changing in such a way that in addition to performing part of business activities by accessing a mail server or web server remotely, most of the in-company business activities are carried out at remote locations.
As one approach to address such a work system, a system operation method called client/server architecture may be introduced. A client/server architecture system is also called a network computing system or server based computing system, in which main programs and data are stored on servers and manipulated from clients such as PCs or thin-clients. In client/server architecture, computing and data storage are performed primarily on the servers, which reduces the need for and frequency of tasks on the clients, such as thin-clients, that would be otherwise necessary, including upgrade and bug fix for the OS and business applications as well as combating and disinfecting viruses, resulting in reduced overall management cost and increased security (See, for example, Japanese Patent Laid-open Publication No. 2005-12775).